The lure of computer drills like Brain Age is hard to resist: play a reasonably compelling set of games for a few hours a week, and train your brain to perform better, much in the same way that hitting a gym works for athletes. And the experience is generally great—for most users, performance numbers do improve. But a question has lingered over this genre of software like a dark cloud: do these tests actually improve general mental performance, or are you just learning to perform a limited set of drills better? To get an answer, a group of researchers in the UK crowdsourced the audience of a science-themed TV show, and set them to work training their brains. Among that crowd, performance on the specific training exercises shot up, but there was little spillover into even closely related skills.